There is a question I have about projected future soil infertility. I think everyone knows there could be a deep connection between soil fertility and animal manure. As species across the world decline in population. There is a decreased volume of animal manure reaching soils. Which could cause soil to become infertile.
One example of this is the widespread devastation of bison herds in north america. Prior to european settlers decimating their populations, it was said that bison herds in north america flocked together like locusts in their annual migration across the continent. Reduced bison herds lead to reduced bison manure which contributes towards reduced soil fertility.
But even as far back as 100 years ago, it was still very common for many to reside in independent farming communities with many animals to maintain relative fertility of soil. More recently the social exodus from farms to cities and modern living may correlate with lower populations of animals per square acre (hectare). Which could correlate with reduced square footage of arable land across the globe.
But to be honest, I can't say I've looked very far into this topic.
It is known that independent farmers in remote desert locations have succeeded in growing many acres of forestland in areas where it was considered impossible to do so.
Different soil types exist around the world, and soil scientists and agronomists use different methods to restore them. In some cases, fertilizing the soil is used, and in others, fertilizing the crop, depending on the requirements of the particular crop. We can also use chemical fertilizer, mulch, mycohhriza, and many other methods besides animal manure. Moreover, they are effective in managing soils. In general, herbivorous animal dung is more beneficial for soil than other animal remains.